Algorithmic Issues in Power Management by Speed Scaling (APM)

3G和Wi-Fi等移动设备的新技术带来了新的生活，改变了用户体验。然而，这种发展可能会受到电池寿命的阻碍，例如，使用3G通信可以将手机的通话时间缩短高达75%。电池容量跟不上设备电源需求的持续增长。此外，设备运行时会产生大量热量。一般来说，设备的功率越大，产生的热量就越多。过热会损害电子设备的寿命。因此，电源管理对现代计算设备的设计造成了重要的限制。为了在不显著牺牲性能的情况下降低能耗，节能意识成为一个至关重要的概念：系统应该只提供所需的服务，以避免多余的能耗。动态电压/速度调节(DVS)成为一种常用的功耗管理技术，例如，AMD、Intel和Transmeta的当前处理器允许处理器以不同的处理器速度运行。DVS的动机是由于众所周知的立方根规则，该规则规定所消耗的功率大致是操作速度的立方。简单地拥有支持DVS的处理器并不能解决问题，因为最重要的问题是如何动态调整处理器的速度，以最低的能量和温度保持性能？虽然已经提出了一些算法解决方案，但大多数都假设处理器可以以任何(无限)速度运行，这在实践中显然不是这样的。此外，到目前为止，所考虑的模型优化了能量或温度，但不是两者都优化。目前的提案旨在提供算法解决方案，以促进功能更强大但能源效率更高的设备。具体目标包括1.开发能源和温度高效调度的准确抽象模型，2.设计具有数学可证明性能保证的算法，以及3。该项目的成功将影响到延长移动设备的电池寿命，从而改善它们可以支持的服务(例如，多媒体)。王博士在作业调度方面的经验，特别是她对节能截止日期调度的初步研究，为项目的成功奠定了良好的基础，预计将是项目成功的关键。

New technologies for mobile devices like 3G and Wi-Fi has brought new life changing user experiences. However, this development can be hindered by battery life, for instance, using 3G communication can shorten the talk time of mobile phones by up to 75%. Battery capacity is not able to catch up with the continuous growth of power requirements for devices. Furthermore, a large amount of heat is generated by device operation. In general, the more powerful the device is, the more heat is generated. Overheating can damage the life of electronic devices. Therefore, power management has imposed important design constraints on modern computing devices. To reduce energy consumption without sacrificing performance significantly, energy awareness'' becomes a crucial concept: a system should only deliver the required service so as to avoid superfluous energy consumption.Dynamic voltage / speed scaling (DVS) becomes a common technique to manage power consumption, e.g., current processors from AMD, Intel and Transmeta allow the processors to operate at various processor speeds. The motivation of DVS is due to the well known cube-root-rule which states that the power consumed is roughly the cube of the operating speed. Simply having processors that support DVS does not solve the problem because the most important question is How to dynamically adjust the speed of processor to maintain performance with the minimal energy and temperature?'' Although some algorithmic solutions have been proposed, most of them assume that the processor can operate at any (unbounded) speed, which is obviously not the case in practice. Furthermore, the models considered so far optimize either energy or temperature but not both. The current proposal aims at providing algorithmic solutions so as to facilitate more powerful, yet energy effective, devices. Specific objectives include1. developing an accurate abstract model of energy and temperature efficient scheduling,2. designing algorithms with mathematically provable performance guarantees, and3. providing a comprehensive evaluation of the proposed algorithms.The success of this project will impact on extending the battery life of mobile devices thus improving the services (e.g., multimedia) that they can support. The experience of Dr.\ Wong on job scheduling, in particular, her preliminary study on energy efficient deadline scheduling serves as a good foundation and is expected to be crucial for the success of the project.